Carousel 1
An object makes 20 revolutions per second. How much time does it take to make one revolution?
0.05 seconds
Centripetal force acting on an object is 5 N. The mass of the object is 100 grams. What is the centripetal acceleration?
50 m/s/s
A single force of 10 N is acting on an object. What is the net force acting on the object?
10 N
What is the numerical value of the universal gravitational constant?
6.67x10-11 m2N/kg2
This living animal has the heaviest brain...
A: African Bush Elephant
B: Black Rhinoceros
C: Sperm Whale
D: Human
Sperm Whale. They have the heaviest brain of any living animal. The average Sperm Whale's brain weighs more than 20 pounds (9 kilograms) which is about 4 times heavier than the average human brain.
You are on a circular track that has a radius of 20 meters. If you move at a constant speed of 10 m/s how much time does it take to complete one full turn?
12.56 seconds
Gina likes to build and fly motorized model airplanes with her Dad. She holds a 3.00-m long string on one end that is attached to a 272-gram plane on the other end. She pulls with a force of 3.46 N as it rotates in a circle. The string can be considered horizontal. What is the plane's speed?
6.2 m/s
A horizontal force of 15 N is applied to a block. The block moves at a constant speed. What is the net force acting on the block?
0 N
What is the force of attraction between the Earth and the Moon? The mass of the Moon is 7.35x1022 kg, the mass of the Earth is 5.97x1024 kg, and the distance between the Earth and the Moon is 384400 km.
1.98x1020 N
This English chemist and physicist discovered hydrogen.
A: Sir William Crookes
B: Henry Cavendish
C: Dorothy Hodgkin
D: Bernard Shaw
Cavendish. This English chemist and physicist not only discovered hydrogen, but also determined the mass of the Earth.
Angular velocity shows how fast an object rotates. Its formula is given as \omega=v/R, where v is speed, and R is the radius. A car moves around a circular path at 15 m/s. The diameter of a circle is 0.1 km. Calculate angular velocity.
0.3 rad/s
Mr. Chowder grips a 7.70-kg bowling ball and stands on a rotating platform. A student gives the platform a spin and Mr. Chowder holds the ball 0.785 m from the circle's center where it moves at a speed of 2.00 m/s. With what magnitude of force must the ball be pulled inward in order to maintain this circular motion?
39.2 N
A horizontal force of 15 N is applied to a block. The block moves at a constant speed. What is the friction force acting on the block?
15 N
What is the acceleration due to gravity on Mars? The radius of Mars is 3,389.5 km, and the mass is 6.39 × 1023 kg.
3.71 m/s/s
The three main parts of a comet are the nucleus, the tail, and the
A: Zenith
B: Umbra
C: Radiant
D: Coma
Coma. The coma consists of gases and dust around the nucleus.
Calculate the speed at which the Earth moves around the Sun. The distance between the Sun and the Earth is 147.4 million kilometers.
29.4 km/s
In the display window of the toy store at the local mall, a battery-powered plane is suspended from a string and flying in a horizontal circle. The 339-gram plane makes a complete circle every 1.81 seconds. The radius of the circle is 1.30 m. Determine the centripetal force
5.35 N
In a rare moment of confusion, Alejandro's sleigh dogs begin pulling in random directions. At one moment, there are three forces exerted by the dogs on the sled. There is a 225.0 N force to the east, a 383.0 N force to the west, and a 320.0 N force to the east. What is the magnitude of the net horizontal force on the sled?
162 N
What should the radius of an unknown planet be so that the acceleration due to gravity on that planet is 3 times less than that of Earth? The mass of the planet is the same as Earth's.
1.73 times
This animal has the highest blood pressure...
A: Giraffe
B: Blue Whale
C: Elephant
D: Flea
Giraffe. Because of its extremely long neck, the giraffe must rely on its oversized heart (two feet long and twenty-five pounds!) to pump blood all the way to its head. As a result, the giraffe has the highest blood pressure of any animal: 280/180 mmHg (millimeters of mercury) at heart level when prone -- more than twice the blood pressure of an average human. Not surprisingly, because of their high blood pressure, giraffes are prone to heart attacks.
A barrel rider is moving in a circle with a speed of 7.5 m/s. The acceleration of the rider is 8.8 m/s/s. The speed of the object is somehow increased to 15.0 m/s (i.e., doubled). The new acceleration would be
35.2 m/s/s
A loop de loop track is built for a 499-kg roller coaster car. It is a completely circular loop that is 27.3-m tall at its highest point. The car successfully completes the loop with an entry speed (at the bottom) of 30.6 m/s. If the speed of the car at the highest point is 20.0 m/s, what is the normal force acting on the car at the top of the loop?
9.7 kN
Four forces act on an object. 20 N to the North, 10 N to the South, 15 N to the East, and 9 N to the West. What is the net force?
11.7 N
Mike's weight on Earth is 800 N. What would be his weight if the mass of the planet increased by 9 times and the radius of the planet increased 3 times
800 N
The first Earth Day was celebrated in this year...
A: 1950
B: 1960
C: 1970
D: 1980
1970. The first Earth Day was celebrated on April 22, 1970, and has been celebrated each year following on April 22nd. The original purpose of Earth Day was to inspire people to think and act more environmentally. Earth Day falls on or around the birthdays of several environmental spokespersons.