Mr W's Online Physics Quiz 3

Force is the correct answer because it refers to any push or pull. Force is a vector quantity that can cause an object to accelerate, decelerate, or change direction. It can be measured in units such as Newtons. In physics, force is a fundamental concept and plays a crucial role in understanding the motion and interactions of objects.

Gravity is the force that pulls all objects together. It is a fundamental force of nature that exists between any two objects with mass. Gravity is responsible for the attraction between objects on Earth, causing objects to fall towards the ground and keeping the planets in their orbits around the sun. In contrast, inertia is the tendency of an object to resist changes in its motion, momentum is the product of an object's mass and velocity, and net refers to the overall result or total of something.

Friction is the force that resists motion when two objects are in contact. It occurs due to the roughness of the surfaces in contact, causing resistance and making it harder for the objects to slide or move past each other. Friction is present in various everyday situations, such as when walking, driving a car, or sliding objects on a table. It plays a crucial role in determining the efficiency and effectiveness of many mechanical systems.

The correct answer is 64 km/hr West because velocity is a vector quantity that includes both magnitude (speed) and direction. In this case, the rider traveled 1024 km in 16 hours, so the magnitude of the velocity is 1024 km/16 hr = 64 km/hr. The direction is specified as West, indicating that the rider traveled towards the West direction.

The average running speed for the weekend is calculated by dividing the total distance covered by the total time taken. In this case, the total distance covered is 15km + 8km + 7km = 30km, and the total time taken is 3 hrs + 2 hrs + 1 hr = 6 hrs. Therefore, the average running speed is 30km/6hrs = 5 km/hr.

The correct answer is 47 kph. This is because the question asks for the speed at which the person is driving the snowmobile. The given information states that the person drives 187km in 4 hours, which means their speed is calculated by dividing the distance traveled by the time taken. Therefore, the speed is 187km/4 hours = 47 kph.

The unit to measure weight in the metric (SI) system is the newton. The newton is the derived unit of force in the SI system, and it is defined as the force required to accelerate a one-kilogram mass by one meter per second squared. It is commonly used to measure the weight of objects, as weight is a force caused by the gravitational pull on an object. The kilogram is the unit to measure mass, not weight. The pound is a unit of weight in the imperial system, not the metric system. The liter is a unit of volume, not weight.

The child's average speed can be calculated by dividing the total distance covered by the total time taken. In this case, the child runs a total distance of 22m + 42m = 64m in a total time of 4s + 12s = 16s. Therefore, the average speed of the child is 64m/16s = 4m/s.

Inertia refers to the resistance of an object to changes in its state of motion. It is a property of matter related to mass, as objects with more mass have more inertia. Therefore, inertia can be considered as another word for mass.

The acceleration of the plane can be calculated using the formula: acceleration = (final velocity - initial velocity) / time. In this case, the final velocity is 18 m/s, the initial velocity is 4 m/s, and the time is 7 seconds. Plugging these values into the formula, we get: acceleration = (18 m/s - 4 m/s) / 7 s = 14 m/s / 7 s = 2 m/s/s. Therefore, the correct answer is 2 m/s/s.