Possibly bad wheel bearing.
Sticky caliper's... Check your break calipers...
Brakes
The brakes are the primary cause of stopping a car whilst driving.
This is probably due to worn brake rotors on the brakes, if there is no vibration when driving then this will be the cause.
Brakes.
yes, its really risky because driving with bad brakes can probably cause a hydraulic failiure your brakes can fail and you dont want to know what happens so get your brakes checked
The most likely cause is a warped rotor. It can also be other things so have you brakes and suspension inspected.
If you are driving on wet roads there is no way to avoid those effects. Most brakes dry out very quickly when applied.
Sudden and harsh braking movements can cause the wheels to lock. When the rubber tires rub against gravel, the resulting friction can cause a loud screech.
Check with a tire store and see if you need an alignment.
Either warped rotors or drums can cause pulsating. Apply the parking brake slowly while going about 15mph and see if t pulsates. If it does, it is the drums that need turning. If not, it is the rotors that need turning.
YOU WILL WEAR YOUR PADS OUT PREMATURELY AND MAY CAUSE HOT SPOTS TO FORM IN THE ROTORS. HOTS SPOTS BECOME HARDER THAN THE REST OF THE ROTOR AND WILL CAUSE THE PEDAL TO HAVE A BUMPING FEELING WHEN YOU APPLY THE BRAKES. THE ROTOR WILL THEN HAVE TO BE REPLACED TO SOLVE THE PROBLEM. ALL IN ALL YOU SHOULD HAVE THE PROBLEM CHECKED AND REPAIRED ASAP. BRAKES ARE NOT A GOOD THING TO GAMBLE WITH FOR SURE.