A. I looked it up and it should be somewhere around A
Rock is completely immersed in hot water. By the second law of thermodynamics, thermal energy or heat is transferred from substance with higher temperature to substance with lower temperature until they come to thermal equilibrium i.e. both at same temperature.
It is given here that rock is at 20°C which is at lower temperature than water at 80°C. ∴Heat or thermal energy flows from water to rock. So, right choice is-
A. The water gives the rock thermal energy and gets no thermal energy in return.
Answer:
The vertical distance that the ski jumper fell is 417.45 m.
Explanation:
Given;
initial horizontal velocity of the jumper, = 26 m/s
horizontal distance of the jumper, dx = 240 m
The time of the motion is given by;
dx = Vₓt
t = dx / Vₓ
t = 240 / 26
t = 9.23 s
The vertical distance traveled by the diver is given by;
initial vertical velocity, , = 0
Therefore, the vertical distance that the ski jumper fell is 417.45 m.
Work is calculated by multiplying force by the distance that the object had moved. The applied force is 60 N, moving the object by 10 m. Thus, the work does is 600 J. For the friction force which is equal to,
100N x 0.250 = 25.0 N
the work done is,
W = (60 N - 25 N) x 10 m = 350 J
The kinetic energy of the box can be equated to this force. Thus, the answer is also 350 J.
Answer:
r = 58.44 [m]
Explanation:
To solve this problem we must use the following equation that relates the centripetal acceleration with the tangential velocity and the radius of rotation.
a = v²/r
where:
a = centripetal acceleration = 15.4 [m/s²]
v = tangential speed = 30 [m/s]
r = radius or distance [m]
r = v²/a
r = 30²/15.4
r = 58.44 [m]