Apple hits the surface with speed 16.2 m/s
The angle made by the apple velocity with normal to the incline surface is given as 20 degree
now the component of velocity which is parallel to the surface and perpendicular to the surface is given as


so here we have


<em>so its velocity along the incline plane will be 5.5 m/s</em>
Answer:
-120000 W
Explanation:
Power = change in energy / time
P = ΔE / t
P = (½ mv₂² − ½ mv₁²) / t
P = m (v₂² − v₁²) / (2t)
Given m = 1.5 t = 1500 kg, v₂ = 10 m/s, v₁ = 30 m/s, and t = 5 s:
P = (1500 kg) ((10 m/s)² − (30 m/s)²) / (2 × 5 s)
P = -120000 W
Answer:
75 rotations
Explanation:
f0 = 0, f = 3000 rpm = 50 rps, t = 3 s
(a) use first equation of motion for rotational motion
w = w0 + α t
2 x 3.14 x 50 = 0 + α x 3
α = 104.67 rad/s^2
(b) Let θ be the angular displacement
use second equation of motion for rotational motion
θ = w0 t + 1/2 α t^2
θ = 0 + 0.5 x 104.67 x 3 x 3
θ = 471.015 rad
The angle turn in one rotation is 2 π radian.
Number of rotation = 471.015 / (2 x 3.14) = 75 rotations
Newton's second law states that the resultant of the forces applied to an object is equal to the product between the object's mass and its acceleration:

where in our problem, m is the mass the (child+cart) and a is the acceleration of the system.
We are only concerned about what it happens on the horizontal axis, so there are two forces acting on the cart+child system: the force F of the man pushing it, and the frictional force

acting in the opposite direction. So Newton's second law can be rewritten as

or

since the frictional force is 15 N and we want to achieve an acceleration of

, we can substitute these values to find what is the force the man needs:
Answer:5
Explanation:
Given
speed of object 
radius of circle 
Force towards the center 
Work done is given by the dot product of Force and displacement
and we know know displacement of the object is along the circle which is perpendicular to the force acting therefore Work done will be zero

