Could somebody check if the answers to these questions are correct?
1)an object of single substance with mass 10kg and moving horizontally with speed 10m^-1 hits a wall and stops. internal friction cause the object to increase temperature by 0.1k. find specific heat capacity, in Jkg^-1K^-1.
o.5mv^2= ∆U
∆U = C∆T
500= ∆U
C∆T= 500
C∆T =mc∆T
500= mc∆T
c= 500 Jkg^-1K^-1.
2) a car of mass 1000kg is initially at vertical heigh h1= 10 metres and is moving down a slope, with the engine off, at initial speed 10ms^-1. The brakes are used, causing an increase in internal energy of 1.3 x 10^5 J and the car comes to a rest at vertical heigh h1. find h1, assuming no other effects occur.
g= 10m s^-2
∆E = ∆Ek + ∆Ep + ∆U
∆E=0
∆Ek + ∆Ep = -∆U
5000+ 10000(h1-10)= 1.3 x 10^5
h1=2.5 metres