Answer:
The maximum static frictional force is 40N.
Explanation:
When an object of mass M is on a surface with a coefficient of static friction μ, there is a minimum force that you need to apply to the object in order to "break" the coefficient of static friction and be able to move the object (Called the threshold of motion, once the object is moving we have a coefficient of kinetic friction, which is smaller than the one for static friction).
This coefficient defines the maximum static friction force that we can have.
So if we apply a small force and we start to increase it, the static frictional force will be equal to our force until it reaches its maximum, and then we can move the object and now we will have frictional force.
In this case, we know that we apply a force of 40N and the object just starts to move.
Then we can assume that we are just at the point of transition between static frictional force and kinetic frictional force (the threshold of motion), thus, 40 N is the maximum of the static frictional force.
Answer:
Friction
Explanation:
friction is the force that tries to slow things down when two things are rubbed together.
Answer:
(1) 14.12 m/s
Explanation:
Given:
= initial speed of the ball = 16 m/s
= angle of the initial speed with the horizontal axis = 
= initial height of the ball from where Julie throws the ball = 1.5 m
= final position of the ball where Sarah catches the ball = 1.5 m
Let us assume the following:
= horizontal component of the initial speed
= vertical component of the initial speed
= horizontal acceleration of the ball
= vertical acceleration of the ball
The given problem is projectile motion. When the ball is thrown from the air with a speed of 16 m/s at an angle 28 degree with the horizontal axis. When the ball is in the air, it experiences an only gravitational force in the downward direction if we ignore air resistance on the ball.
This means if we break the motion of the ball along two axes and study it, we have a uniform acceleration motion in the vertical direction and a zero acceleration motion along the horizontal.
Since the ball has a zero acceleration motion along the horizontal axis, the ball must have a constant speed along the horizontal at all instant of time.
Let us find out the initial velocity horizontal component of the velocity of the ball. which is given by:
As this horizontal velocity remains constant in the horizontal motion at all instants of time. So, the horizontal component of the ball's velocity when Sarah catches the ball is 14.12 m/s.
Hence, the horizontal component of the ball's velocity when the ball is caught by Sarah is 14.12 m/s.
The correct answer is (a.) a parsec. A parsec is a distance an object would be from Earth if its parallax were one arcsecond. This unit of measurement is usually used in astronomy which makes it easier for astronomers to calculate or measure in space accurately.
Things are rubbed against each other
