Answer:
m = 2218.67 kg
Explanation:
It is given that,
Initial velocity, u = 7.5 m/s
Final speed of an object, v = 0 (at rest)
Force, F = 5.2 kN
Time, t = 3.2 s
We need to find the mass of the object. Force acting on an object is given by :
F = ma
m is mass, a is acceleration
So, the mass of the object is 2218.67 kg
Answer:
78.498N
Explanation:
The Net force provided by the spinnaker can be obtained from Newton's second law of motion as follows;
where m is the mass, v is the final velocity, u is the initial velocity and t is the time interval for which the force acted.
Given;
m =980lb
v = 12mi/h
u =8mi/hr
t = 10s.
It is important to convert all quantities to their SI units where necessary, so we do that as follows;
1lb = 0.45kg,
hence 980lb = 980 x 0.45kg = 441kg.
1mile = 1609.34m
1hour = 3600s,
therefore;
Substituting all values into equation (1), we obtain the following;
Answer:
Work done by the frictional force is
Explanation:
It is given that,
Mass of the car, m = 1000 kg
Initial velocity of car, u = 26.1 m/s
Finally, it comes to rest, v = 0
We have to find the work done by the frictional forces. Work done is equal to the change in kinetic energy as per work - energy theorem i.e.
W = −340605 J
or
Hence, the correct option is (a).