Answer:
The final velocity is 28.14 m/s
Yes the angle of projection matters
Explanation:
Given;
initial velocity of the water balloon, u = 20 m/s
height of the building, h = 20 m
let the final speed of the ball when it hits the ground = v
The final speed is calculated as follows;
v² = u² + 2gh
v² = (20)² + 2(9.8)(20)
v² = 400 + 392
v² = 792
v = √792
v = 28.14 m/s
Yes the angle matters, if the balloon had been dropped at a certain angle, the final velocity would have been estimated using the following formula;

where;
θ is the angle of projection, which accounts for the vertical component of the velocity.
Answer:
The ball has an initial linear kinetic energy and initial rotational kinetic energy which can both be converted into gravitational potential energy. Therefore the hill with friction will let the ball reach higher.
Explanation:
The ball has an initial linear kinetic energy and initial rotational kinetic energy which can both be converted into gravitational potential energy. Therefore the hill with friction will let the ball reach higher.
This is because:
If we consider the ball initially at rest on a frictionless surface and a force is exerted through the centre of mass of the ball, it will slide across the surface with no rotation, and thus, there will only be translational motion.
Now, if there is friction and force is again applied to the stationary ball, the frictional force will act in the opposite direction to the force but at the edge of the ball that rests on the ground. This friction generates a torque on the ball which starts the rotation.
Therefore, static friction is infact necessary for a ball to begin rolling.
Now, from the top of the ball, it will move at a speed 2v, while the centre of mass of the ball will move at a speed v and lastly, the bottom edge of the ball will instantaneously be at rest. So as the edge touching the ground is stationary, it experiences no friction.
So friction is necessary for a ball to start rolling but once the rolling condition has been met the ball experiences no friction.
Answer:
The aeroplane flew 4200 miles for 7 hours.
600 times 7 is 4200.
Answer:
684J
Explanation:
So basically the formula for gravitational potential energy is Mass X Gravity X height. That is G.p.e = mgh
We don't have the mass but since we have the height, we multiply directly with the height since the quantity of weight is already given.
so G.p.e = 360 X 1.9 = 684J
Note that; The answer is in joules because g.p.e is work done.
Hope that was helpful!!