Which is not expecting acceleration? a point on the outside of a spinning top whose rotational speed is constant. a skydiver whose air resistance is equal to that of her weight. a car on the freeway experiencing a net force of -120 n. a submerged beach ball whose buoyant force is eight times the force of gravity on it. which is a valid internal frame of reference? a frictionless spinning merry go round. a falling rock. a hot air balloon moving at 30 degrees east of north with no net force. a space shuttle whose boosters just ignited for takeoff. two teams are playing tug of war. the team on the right is pulling with 4320 n. the team on the left is pulling with 4380 n. which direction does the rope move and with what force? 60n to the right 120n to the left 60 n to the left 120 n to the right

#1

A point on the outside of a spinning top whose rotational speed is constant.

Since the point at the top is at rest so it will not accelerate at all

A skydiver whose air resistance is equal to that of her weight.

Since weight is counter balanced by air resistance so net force on it is zero so acceleration will be zero

A car on the freeway experiencing a net force of -120 N.

Since net force is not zero so it will accelerate here

A submerged beach ball whose buoyant force is eight times the force of gravity on it.

Since buoyant force is more than the weight so it will not at rest and move upwards with some acceleration

#2

A frictionless spinning merry go round.

Since spinning wheel accelerating due to centripetal force so it is non inertial frame

A falling rock.

Falling rock is accelerating due to gravity so it is again non inertial frame

A hot air balloon moving at 30 degrees east of north with no net force.

since hot air balloon is having no force on it so its acceleration is zero and its an inertial frame

A space shuttle whose boosters just ignited for takeoff.

Since space shuttle is accelerating due to boosters so it is non inertial frame

#3

Here net force on it is due to two given forces

towards right

towards left

so here net force is given as

since force towards left is more so the direction will be towards left

so correct answer is 60 N towards left

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.