Answer:a) 34.5 N; b) 24.5 N; c) 10 N; d) 1J
Explanation: In order to solve this problem we have to used the second Newton law given by:
∑F= m*a
F-f=m*a where f is the friction force (uk*Normal), from this we have
F= m*a+f=5 Kg*2 m/s^2+0.5*5Kg*9.8 m/s^2= 34.5 N
then f=uk*N=0.5*5Kg*9.8 m/s^2= 24.5N
the net Force = (34.5-24.5)N= 10 N
Finally the work done by the net force is equal to kinetic energy change so
W=∫Force net*dr= 10 N* 0.1 m= 1J
The FREQUENCY of light remains unchanged once it leaves the source.
Motion of a ball thrown by a person upwards and caught after some time is an example of motion in which displacement of the particle is zero but acceleration is not zero in journey.
The displacement of the ball is zero because the starting and end point of the motion are same, i.e, the person's hands.During its motion, the acceleration of ball is constant and non zero called as acceleration due to gravity, g= -9.8 m/s². The velocity of ball is continuously changing. It first decreases during the upward motion of the ball and then increases during the downward journey.The acceleration remains constant and non zero all the time.
Answer:
We know that potential energy of a body;
= mass(m)× gravitational acceleration(g) × height(h)
Lets find out the mass of the body
P.E. = mgh
=> 6500J = mass × 9.8m/s^2 × 12m
=>6500J = mass × ( 9.8 × 12 ) × ( m/s^2 × m)
=> 6500 Nm = m × 117.6 × m^2 / s^2
=> 6500/117.6 Ns^2/m = mass [°.° Ns^2/m = kg]
=> 55.272 Kg = mass
Therefore the mass of the body = 55.272 kg ~ <em>6</em><em>0</em><em> </em><em>k</em><em>g</em><em> </em>(Ans)
Hope it helps you
