1) Answer D not at all
The car is not experiencing any frictional force so that implies that there is no force acting on the car once it starts motion. So, according law of inertia, the car will continue to move and no other force is required.
Friction force is the resistance force that opposes the motion of any object. It arises due to the contact of surfaces.
2) Answer C none
There is no force on any spaceship moving far from any planet. So, according to law of inertia the spacecraft will continue to move at same speed.
Law of inertia states that any object keeps in the state of motion or rest unless a non zero external force is applied on it.
Weight Force of Junior = m g = 115kg x 9.81 m/s^2 = 1128.15N then
compute for the friction force
Friction Force= WF x (coefficient of kinetic friction) = 1128.15N x 0.35 = 394.8525N or 395N
But you can compute in a straightway:
Solution:
= 115 x 9.81 x 0.35
= 394.85
= 395 N
It will still give the same results.
Answer:
C)Earth's orbital speed is greater when it is closer to the Sun than when it is farther from the Sun.
Explanation:
We can use Kepler's 2nd law or the law of area to answer this question.
The law states that the rate of area swept out by a planet's orbit is same throughout the orbit. For the farthest point since the distance is large as compared to to the nearest point, the possibility that area swept is large. Hence, to compensate the extra swept area. the orbital speed has to decrease at the largest point.
Hence, planet's speed is greater when it is closer to sun than the speed when it is farther.
89 degrees Fahrenheit would be 31.7 degrees Celsius!
