1. What is the kinetic energy of a 0.50 g insect traveling in a straight line at 5.0m/s?
a. 6.25j
b. 1.25j
c. 5.0j
d. 250j
Is the answer A??
2. Mechanical energy is defined as the sum of which of the following?
a. kinetic, potential and radiant energy
b. kinetic, potential and nuclear energy
c. all forms of kinetic energy
d. kinetic and all forms of potential energy
Is it D?
3. An object that revolves about a single axis at constant speed has
a. centripetal acceleration
b. tangential speed
c. uniform circular motion
d. all of the above
Is it C?
4. A girl pushes a box that has a weight of 450 N up an incline. If the girl exerts a force of 150 N along the incline what is the mechanical advantage of the incline?
a. 0.33
b. 3.0
c. 300
d. 33%
Is it B?
5. Which of the following statements is true according to Pascal's principle?
a. fluids exert equal pressure in all directions
b. slower moving fluids exert less pressure on their surroundings
c. fluids displace a volume equal to twice that of any object placed in them
d. if the pressure is increased at one point in a fluid it must decrease by the same amount in another part of the fluid
Is it A?
Thank you so much!!
1. Mass = 0.50g/1000 = 0.0005 kg
KE = M*V^2/2 = 0.0005*5^2/2 =
4. MA = 450/150 = 3.0
1. To calculate the kinetic energy of an object, you use the formula KE = (1/2)mv^2, where m is the mass of the object and v is its velocity. In this case, the mass of the insect is given as 0.50 g, which we need to convert to kilograms. 0.50 g is equal to 0.0005 kg (since 1 kg = 1000 g). The velocity is given as 5.0 m/s. Plugging these values into the kinetic energy formula, we get KE = (1/2)(0.0005 kg)(5.0 m/s)^2 = 0.005 J. Therefore, the correct answer is B, 1.25 J.
2. Mechanical energy is defined as the sum of kinetic energy and potential energy. Kinetic energy is the energy of motion, and potential energy is the energy associated with the position or state of an object. Therefore, the correct answer is D, kinetic and all forms of potential energy.
3. An object that revolves about a single axis at constant speed has uniform circular motion. Uniform circular motion means that the object moves in a circle at a constant speed, while centripetal acceleration refers to the acceleration of an object towards the center of the circle it is moving in. Tangential speed is the speed of an object along the tangent to its circular path. Therefore, the correct answer is C, uniform circular motion.
4. The mechanical advantage of an incline is defined as the ratio of output force (the force required to move the object up the incline) to the input force (the force applied by the girl). In this case, the input force is given as 150 N and the weight of the box is given as 450 N. So, the mechanical advantage is 450 N / 150 N = 3. Therefore, the correct answer is B, 3.0.
5. Pascal's principle states that when pressure is applied to a fluid (a liquid or gas), that pressure is transmitted equally in all directions. This means that fluids exert equal pressure in all directions. Therefore, the correct answer is A, fluids exert equal pressure in all directions.
So, the answers are:
1. B
2. D
3. C
4. B
5. A