Answer:
Explanation:
electrical field strength = potential diff / distance
= ( 450 - 0 ) / 8 x 10⁻²
= 5625 V/m
b )
potential difference = electric field x distance
= 5625 x .10
= 562.5 V
A concave lens is a lens that has at least one of its surfaces or both surfaces curved inwards. Due to this reason, this lens diverges the light that falls on it and hence is also called a diverging lens. The concave lens is thinner in the middle compared to its edges. These are used in flashlights, binoculars, telescopes, etc.
Please see attached image for reference.
The given question is incomplete. The complete question is:
Estimate the volume of each ball. Use the formula 
where v is the volume and r is the radius. record the volume in table A of your student guide. The radius of the tennis ball is 2.1 cm and the radius of thr golf ball is 2.0 cm. What is the estimated volume of the table tennis ball in 
What is the estimated volume of the golf ball in
Answer: Volume of the tennis ball is 
and Volume of the golf ball is 
Explanation:
We have to find the Volume of tennis ball and golf ball by using the formula
Radius of the tennis ball = 2.1 cm
Radius of the golf ball =2.0 cm.
Putting the value of radius in the formula , we get:
Volume of the tennis ball = 
Volume of the golf ball = 
Volume of the tennis ball is and Volume of the golf ball is
Answer:
There is absolutely No relationship between the weight of an object (which is constant) and the frictional force. If a block is sliding on a surface, that surface will be exerting a force on the block. That force can be resolved into a component parallel to the surface (which we call the frictional component), and a component perpendicular to the surface (called the normal component). For many situations, we find experimentally that the frictional component is approximately proportional to the normal component. The frictional component divided by the normal component is defined to be a quantity called the coefficient of kinetic or sliding friction. The coefficient of kinetic friction obviously depends on the nature of the surfaces involved. The normal component on an object can be decreased if you pull in the direction of the normal component (the weight does not change). However pulling this way on the object not only decreases the normal component, but it also decreases the frictional component since they are proportional. This is why it is easier to slide something if you pull up on it while you push it. If you push down, the normal and frictional components increase so it is harder to slide the object. The weight of an object is the downward force exerted by Earth’s gravity on that object, and it does not change no matter how you push or pull on the object.
