Answer:
7.7 GJ
Explanation:
Kinetic wnergy is given by
KE=½mv²
Where KE denote kinetic energy, m is the mass of object and v is velocity. Normally, m is in Kg and v in m/s
Conversion
Given speed of satelite in km/h, we convert it into m/s by multiply by 1000/3600
20000*1000/3600=5555.5555555555
Rounded off, m=5555.56 m/s
Substituting 500 kg for m and 5555.56 m/s for v then
KE=½*500*5555.56²=7,716,061,728.4 rounded off as
KE=7.7 GJ
Work needed = 23,520 J
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Further explanation
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Given
height = 12 m
mass = 200 kg
Required
work needed by the crane
Solution
Work is the transfer of energy caused by the force acting on a moving object
Work is the product of force with the displacement of objects.
Can be formulated
W = F x d
W = Work, J, Nm
F = Force, N
d = distance, m
F = m x g
Input the value :
W = mgd
W = 200 kg x 9.8 m/s²x12 m
W = 23520 J
No, it doesn't. Weight (sometimes) indirectly affects the frictional force but not the coefficient. The frictional force is proportional the normal reaction force which often (but not always) is equal to the weight. The constant of proportionality is the coefficient of friction or its reciprocal (depending on which side of the equation the constant is on). Situations when weight and normal reaction force are unequal when they are unequal. Normal reaction force is just a force to maintain the equilibrium of the body if it can.
Answer:
Driver hits the dog
Explanation:
From kinematics equation
and making a the subject
F=ma=800*-4=-3200 N
The driver is required to apply a force of 3200 N to effectively not hit the dog. However, when the driver applies 2000 N, this is less the required force by 1200 N hence the driver hits the dog.