Answer:
The driver hits the stationery dog because the applied force is less than required force
Explanation:
Kinetic energy will be given by
where m is the mass of the vehicle and v is the speed/velocity of the vehicle.
Substituting 800 Kg for m and 20 m/s for v we obtain

Frictional force by vehicle pads is given by
where d is the distance moved
Substituting 160000 for KE and 50 m for d we obtain

Therefore, the vehicle hits the dog since the required force is 3200N but the driver applied only 2000 N
Because the specimen is very small with a light microscope
Answer:
The frequency of the oscillation is 0.9Hz
Explanation:
This problem bothers on simple harmonic motion of a spring
Given data
Mass of the child m= 25kg
Spring constant k=791 N/m
Amplitude a= 31cm
But the period of the motion as a result of the adults sholve is expressed as
T=2π√m/k
T=2*3.142√25/791
T=6.284√0.031
T=6.284*0.176
T=1.11 sec
But frequency F=1/T
F=1/1.11
F=0.9Hz
Answer:
All the three quantities will have non zero joules.
Explanation:
At the initial position of rest the system will have only gravitational potential energy while the other 2 quantities will be zero.
when the system reaches a height (y-h) only kinetic energy will be zero while the other 2 quantities will be non zero
At the position of (y-h/2) all the 3 quantities will be non zero.
To do this we may use things that are good conductors - are painted dull black -
Have a air flow around them Maximised.