Chapter 7

1 / 43

# Chapter 7 - PowerPoint PPT Presentation

Chapter 7. Projectile Motion. Projectile Motion. The motion of an object that has been thrust into air where the only forces acting on it are gravity &amp; air resistance. Projectile Motion. Because we ignore air resistance, the only force acting on thrown objects is gravity. Projectile.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about ' Chapter 7' - chaka

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Chapter 7

Projectile Motion

Projectile Motion
• The motion of an object that has been thrust into air where the only forces acting on it are gravity & air resistance.

Projectile Motion

• Because we ignore air resistance, the only force acting on thrown objects is gravity.

Projectile

• The object that has been given an initial thrust, fired, or thrown into air.

Trajectory

• The path of a projectile as it travels through space.
In Projectile Motion
• The vertical & horizontal components act independently & can be solved independently

In Projectile Motion

• The only force acting vertically is the force of gravity causing downward acceleration.

In Projectile Motion

• There are no net forces acting horizontally; thus, the horizontal velocity is constant.

In Projectile Motion

• Use your velocity formulas to solve for vertical & horizontal motion independently.

In Projectile Motion

• Solve for time in air 1st
• Always use the vertical component to solve for the time in air.

In Projectile Motion

• After solving for the time in air, solve for the range or horizontal distanced traveled

A rock has been thrown horizontally at 4.0 m/s from a tower 49 m high. Calculate: tair, dH, and vH & vV the instant before impact:

A plane flying horizontally at 250 m/s at an altitude of 4.9 km high drops a bomb. Calculate: tair, dH, and vV the instant before impact:

Drill: A ball rolls at 75 cm/s off the edge of a 49 cm table. Calculate: tair, maximum vV,

and dH:

A car traveling at 1500 cm/s goes off the edge of a 0.49 km high cliff. Calculate: tair, dH, and maximum vV:

A car accelerates at 5.0 m/s2 for 250 m before going off the edge of a 0.49 km high cliff. Calculate: t & max v on the ground, & t, dH, and max vV in air:

Drill: A bullet exits a 0.50 m barrel horizontally at 500.0 m/s from a height of 2.0 m. Calculate: (a & t)in barrel, (t, max vV, & dH)in air:

A cannon ball is fired at 1000.0 m/s at 53o from horizontal. Calculate: max height, tair ,vVat impact, dH:

Repeat the last problem with a cannon ball exiting the barrel at the same speed with angles of 40o, 45o, & 50o

tair, hmax, vVmax, dH:

A ball is thrown at 25 m/s at 53o from horizontal. Calculate: vV, vH, tair, hmax, & dH

A 25 Mg car is accelerated from rest at 5.0 m/s2 up a 250 m ramp at 37o from horizontal. Calculate: t, & vf on the ramp, and dV, dH, t, and maximum vV in air:

A 1.0 Mg block slides from rest down a 250 m ramp (m = 0.20) at 37o from horizontal that ends 490 m above the ground. Calculate: t, & vf on the ramp, and dH, t, and maximum vV in air:

A sled coasts off a 0.49 km cliff at

18 km /hr.

Calculate: tair, max vV, & dH:

A catapult launches a 250 kg rock at 100.0 m/s at 37o from horizontal. Calculate: tup, dV, tair, & dH :

Define each of the following

• Distance Displacement
• Speed Force
• Velocity Acceleration

Give Units for each of the following

• Distance Displacement
• Speed Acceleration
• Velocity Force

vf = vi + at

d = vit + ½ at2

A 25 Mg sled slides from rest down a 500.0 m slope (m = 0.10) at 37o from horizontal that ends 2.45 km above the ground. Calculate: t, & vf on the slope, and dH, tair, and the maximum vV in air:

A 250 Mg sled accelerates at 3.0 m/s2 up a 250 m ramp (m = 0.25) at 53o from horizontal. Calculate: Fa, tramp, vf ramp, tair, dv, & dH

A 0.10 Mg cycle is accelerated with a force of 500.0 N for 10.0 s before hitting a 25 m ramp at 37o from horizontal. Draw the system and Calculate: vat bottom & top of ramp, and t, dv, & dH in the air

An airplane is flying horizontally due west at 360 km/hr at an altitude of 0.49 km & drops a 2000 lb bomb. Draw the system and Calculate: tair, maximum vV, & dH.

A 50.0 kg person skis (m = 0.010) down a 3.0 km ski trail with an average slope of 30o. Draw the system and Calculate: a, t, maximum v on the trail

British Ships had cannons with muzzle velocities of 400 m/s while the cannons at Ft McHenry could fire at 500 m/s. The British could elevate to 45o while the Americans could elevate to 18o. Which cannons had the greater range.

Expanding gases produce about 10,000 N of force in a gun barrel. One nation wants to build a cannon that will deliver a 2,000 kg cannon ball 200 km. Calculate the length that the barrel must be. Because you are estimating round g to –10 m/s2.

a

b

A

B

• a = 37o
• = 53o

Y = 1.00 kN

C

X

Y

a

b

FV of A

FV of B

+

FV of C

A

B

FH of A

FH of C

FH of B

C

FH of C

Wx +

FV of C

WY

a

b

A

B

FV of A

FV of B

FH of C

FH of A

C

FH of B

FV of C

FH of C

FV of C

Wx +

FV of C

WY

A 200.0 kg rock is catapulted at 53o from horizontal at about 0.10 km/s. Draw the system and Calculate: t, dv, & dH in the air

A rock is thrown at 37o from horizontal at about 25 m/s. Draw the system and Calculate: t, dv, & dH in the air