PHYSICS ATTACK SET 3

FIGURE 1 shows a 30 N forces, F acting on a box at angle of 25 ^ͦ .Calculate the y-component of the force.

• 12.68 N

• -12.68 N

• 27.19 N

• -27.19 N

A ball kicked at 37 ^ͦ from the ground with velocity 20 ms^-1. Calculate the time takes to hit the ground?

• 2.45 s

• 1.32 s

• 1.23 s

• 2.65 s

A car travelling at 91.0 km h^-1 approaches the turnoff for a restaurant 30.0 m ahead. If the driver slams on the brakes with an acceleration of 6.40 ms^-2, what will be her stopping distance?

• 25.3 m

• 49.9 m

• 176.4 m

• 199.7 m

FIGURE 2 shows an object is moving along the x axis. The graph shows its position from the starting point as a function of time. Various segments of the graph are identified by the letter A, B, C and D. What is the velocity and acceleration of the object at 𝑡=7𝑠?

• −1 𝑚𝑠⁻¹, 0 𝑚𝑠⁻²

• −3 𝑚𝑠⁻¹, 0 𝑚𝑠⁻²

• −1 𝑚𝑠⁻¹, −2 𝑚𝑠⁻²

• −2 𝑚𝑠⁻¹, −2 𝑚𝑠⁻²

A 0.40 kg ball is moving horizontally at a speed of 20 m s^-1. If the ball was stopped in 3.0 ms, calculate the average force exerted on the ball?

• 2.7×10³ 𝑁

• −2.7×10³ 𝑁

• 2.7 𝑁

• −2.7 𝑁

A 220 g blue marble moving with a speed of 7.5 ms^-1 hits a 670 g red marble which is at rest. After the collision, the blue marble moves in opposite direction with speed 3.8 ms^-1. Determine the final speed of the red marble.

• $1.2\ ms^{-1}$

• $-1.2\ ms^{-1}$

• $3.7\ ms^{-1}$

• $-3.7\ ms^{-1}$

FIGURE 3 shows a 3.0 kg crate is on a rough plane inclined 30 ͦ to the horizontal. The crate moves at constant velocity down and when a force, F parallel to the plane is acting on it. The coefficient of kinetic friction between the create and the plane is 0.80. Calculate the magnitude of F.

• 5.67 N

• 3.24 N

• 30.59 N

• 50.97 N

A 90 kg man stands in an elevator that is moving up at a constant speed of 5.0𝑚𝑠⁻¹. Calculate the force exerted by him on the floor?

• 0 N

• 90 N

• 883 N

• 450 N

FIGURE 4 shows a roller coaster car being released from rest at point A. If the surface is smooth, calculate the speed at point B if the speed at C is 10ms^-1?

• 196.2 ms^-1

• 14 ms^-1

• 27 ms^-1

• 25 ms^-1

FIGURE 5 shows a stationary 25 kg box being pulled with force, F of magnitude 100 N with 45 ͦ angle along a 15 m horizontal floor. The frictional force between the floor and the box is 3.0 N. Calculate the net work done on the box?

• 67.7 J

• 1106 J

• 1545 J

• 1016 J