Two or more velocities add by vector sum.
In fact, velocity is a vector, with its own intensity, direction and verse. Therefore, we cannot simply add two velocities by algebraic sum, but we need to decompose them on two axes (if we are in a 2D-plane) and calculate the resultant on each axis, and then calculate the total resultant of the two vectors, which will have its intensity, direction and verse.
Answer: 292.95 J
Explanation:
change in internal energy= Heat transfer - work done
ΔU =Q -PΔV
Here, Q = 0 as there is no heat transfer.
P =2.00 atm = 2.00 × 101235 Pa = 202470 Pa
ΔV = final volume - initial volume = 0.8 V -V = -0.2 V
where V is the initial volume.
Volume of a spherical ball, 
r = d/2 = 23.9 cm / 2 = 0.12 m


Hence, internal energy would change by 292.95 J.
Answer:
The approximate spring constant is 
Explanation:
From the question we are told that
The mass of the person is 
The dip of the car is 
Generally according to hooks law

here the force F is the weight of the person which is mathematically represented as

=> 
=> 
=> 
=> 
Answer:
He traveled 9km
Explanation:
To do this problem you need to use the equation which is Speed= distance/time and this problem gives you the speed which is 18 km/h and it gives you the time 1/2 hour so you write the equation 18= d/ 1/2 which his distance is 9km