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>
We use the kinematic equations,
(A)
(B)
Here, u is initial velocity, v is final velocity, a is acceleration and t is time.
Given,
,
and
.
Substituting these values in equation (B), we get
.
Therefore from equation (A),

Thus, the magnitude of the boat's final velocity is 10.84 m/s and the time taken by boat to travel the distance 280 m is 51.63 s
Answer : The correct option is, (d) 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of copper = 
= specific heat of water = 
= mass of copper = 120 g
= mass of water = 300 g
= final temperature of mixture = 
= initial temperature of copper = ?
= initial temperature of water =
Now put all the given values in the above formula, we get:


Therefore, the temperature of the kiln was, 
Answer:

(Downwards)
(Towards Left)
Explanation:
As we know that beam is in equilibrium
So here we can use torque balance as well as force balance for the beam
Now by torque balance equation at the pivot we can say

As we know that
mg = 1.40 kN
F = 5 kN
so we will have


Now force balance in vertical direction


(Downwards)
Force balance in horizontal direction


(Towards Left)