Answer:
Explanation:
Given
time taken 
Speed acquired in 2 sec 
Here initial velocity is zero 
acceleration is the rate of change of velocity in a given time


Distance travel in this time

where
s=displacement
u=initial velocity
a=acceleration
t=time


so Jet Plane travels a distance of 42 m in 2 s
Answer:
Catapult on the ground: Normal, gravity
Catapult (I'm assuming launching marshmallow): Reaction of Force Applied
Marshmallow: Force Applied
Explanation:
This is the forces that act on a stationary object and a launched object. The catapult may also experience a force friction if your teacher is taking a more practical sense.
Answer:
49.3 m/s
Explanation:
The momentum is defined as the product of the object velocity and its mass.
So the momentum of the truck is

For the car to have the same momentum, its speed must be

Answer:
T=4.24 N.m
Explanation:
Torque is equal to force for distance for sinus of the angle between the direction of the force and the distance, the distance between the mass and the pivot is 1 m, and to obtain the force that is the mass for the gravity in this case, we need to know the component that produces a torque in the pivot
F=0.5 kg* 9.8 m/
= 4.9 N
and we decompose the force in parallel direction to the rod and perpendicular direction to the rod, the magnitude that produces torque is the perpendicular component, because the torque is in function of the sinus
so, we obtain -> Fy= 4.9 N*sin(60)= 4.24 N
and, T= (4.24 N)*(1 m)*(Sin(90))= 4.24 N.m
anothe way to do it is,
T= (4.9 N)*(1 m)*(Sin(60))= 4.24 N.m, and we obtain the same result